Stillwater Sends Letter to Shareholders Highlighting Strong Track Record, Proven Operational Plan and Positive Momentum

Stillwater Mining Company (NYSE:SWC) (TSX:SWC.U) ('Stillwater? or the
'Company?) today announced that its Board of Directors has sent a letter
to shareholders in connection with the Company's 2013 Annual
Shareholders Meeting, which will be held on May 2, 2013.

The letter states how ongoing investment in Montana and the Company's
growth projects against a positive outlook for palladium pricing has
positioned Stillwater to generate superior value for shareholders over
the long-term. Stillwater′s strength is a result of the planning,
disciplined execution and flexibility of a decade long strategy put in
place by the Board and management to properly manage and grow its
complex mining operation.

'We are excited about our prospects in Montana and elsewhere given our
existing operations and expansion projects as well as favorable
long-term pricing trends,? commented Frank McAllister, Stillwater′s
Chairman and Chief Executive Officer. 'Careful financial planning has
given us the security and flexibility required to weather the
unpredictable nature of commodity markets, while remaining fully
committed to, and capable of, growing PGM production in Montana. Price
movement in commodities just this week illustrates how Stillwater′s
current Board and management team, with their industry experience and
financial expertise, are far more qualified to run Stillwater than the
Clinton Group or its poorly vetted director nominees.?

Added McAllister, 'The Clinton Group, for its own purposes, has misled
Stillwater investors by disregarding the strong correlation our share
price has had to the palladium price, tries to rewrite history of the
Company's strategic relationships and dismisses asset validation through
third party investment. They present no true plan to operate the
Company, offer value-destructive ideas and seek to elect director
nominees that have misrepresented their accomplishments. We urge
shareholders to focus on the facts and vote the white proxy for all of
Stillwater′s nominees.?

All shareholders of record as of March 6, 2013 are entitled to vote at
the 2013 Annual Shareholders Meeting. Stillwater encourages all
shareholders to carefully review its definitive proxy filing and other
materials and vote only their WHITE proxy card. For more information
about Stillwater′s 2013 Annual Shareholders Meeting, please visit www.supportstillwater.com.

The full text of the letter follows:

April 17, 2013

Dear Fellow Shareholder:

STILLWATER IS THE STRONGEST IT HAS EVER BEEN

DON′T LET THE CLINTON GROUP PUT YOUR INVESTMENT AT RISK

Stillwater is at an important point in the Company′s history. Over the
years we have transformed Stillwater into a low cost, high volume
palladium producer. We now have a viable platform to promote growth
while carefully managing PGM price volatility. As evidenced by recent
market conditions, Stillwater remains very well-positioned given our
capital reserves, proper planning and flexibility on growth ? all signs
of proper stewardship and management. Over time, palladium′s continued
appreciation versus platinum ? a re-rating that Stillwater′s marketing
efforts helped drive ? will allow us to leverage our expansion projects
and generate significant value for shareholders.

Stillwater′s share price has, and continues to be, highly correlated to
the palladium cycle. Indeed, since 2003 Stillwater′s share price has
increased 450% while the price of palladium has increased 427%. This
result was not by luck. The Company struggled tremendously when faced
with the palladium pricing trough of 2003 because it had no clear
operating plan or strategy ? an issue the Board and management had been
tackling since 2001 after inheriting substantial planning, operating and
cost challenges from prior management. The correlation reflects the
significant accomplishments of the Company over the long-term.

Furthermore, even as we invest in our business and develop both new and
existing projects, Stillwater has an exceptional record of cost
management. We have managed costs better than our PGM peers and other
North American hard rock miners. We have also maintained a consistent
level of G&A in our core business while implementing an even more
rigorous safety program and building a workforce and infrastructure to
support our growth initiatives in Montana.

Your Board of Directors has a deliberate and detailed plan to create
value for shareholders, hinging directly on Stillwater′s unrelenting
focus on growing its Montana operations. 87% of the Company′s 2013 $173
million capital budget will be spent on growing its PGM operations in
Montana. Stillwater remains staunchly committed to Montana as the
cornerstone of the Company′s strategic plan and the engine for future
growth and value creation.

THE CLINTON GROUP HAS NO VIABLE PLAN FOR STILLWATER

As we have stated, we value the opinions of our investors and welcome
feedback on a variety of topics. However, we believe that the Clinton
Group, a hedge fund that only recently acquired just 1.3% of the
Company′s outstanding shares, has launched a
self-serving attack on Stillwater and has presented no plan, no suitable
slate of nominees and no qualified CEO ? a very dangerous combination
for shareholders that creates tremendous risk.

The Clinton Group has merely disclosed a disjointed set of 'ideas? for
Stillwater to willingly adopt which collectively do not represent a
coherent alternative strategy to the one your management and Board are
pursuing. In our own analysis, many of these ideas will be
value-destructive for Stillwater′s shareholders.

For example, the Clinton Group has proposed:

• Imposing pricing collars, which would decrease investors′
  commodity exposure and take away the full PGM price upside
  
• Immediately tendering for the convertible debt, which would be
  expensive and leave Stillwater poorly capitalized in the midst of its
  Montana growth projects
  
• Immediately issuing dividends or repurchasing shares, which
  would preclude Stillwater from making investments in PGM growth
  without increasing leverage
  
• Converting Stillwater to an MLP, which would be an unattractive
  option given the volatility and capital requirements of our business ?
  not to mention the complete lack of precedent precious metal MLPs
  
• Proceeding immediately with eight different Montana growth projects,
  many of which are not yet permitted and certainly do not have
  completed engineering. This type of undisciplined approach:
  
• 
  Ignores the lack of available and experienced manpower needed
  
• 
  Ignores mine logistics and planning
  
• 
  Ignores the quality of ore reserves
  
• 
  Ignores the fact that some projects require years of permitting after
  careful work with our neighbors and regulators
  
• 
  Shows that the Clinton team has no appreciation for the complex
  engineering requirements of mine development
  

The Clinton Group also chooses to obscure the fact that Stillwater
remains extremely well-capitalized to fund our PGM operations and future
growth, while other precious metal companies are struggling and are
beset with write-offs and financing constraints. Indeed, the convertible
debt funding we executed in October 2012 was a critical piece of our PGM
growth strategy and enabled us to remain flexible in the face of
commodity price volatility. The Clinton Group would have you believe
that it was a bet against the future performance of the Company. To the
contrary, it was a prudent and disciplined financing decision ? far more
advantageous than taking on high-yield debt with restrictive covenants ?
and it provides Stillwater a low-coupon piece of paper, the principal of
which can ultimately be repaid in cash, negating any potential
shareholder dilution.

The Clinton Group also fabricated an entire history in regards to
Stillwater′s relationship with MMC Norilsk Nickel, claiming that Norilsk
had operating control over the Company. In contrast, Stillwater and
Norilsk collaborated in an effective and brilliant marketing arrangement
that ensured palladium′s continued and increasing use in the U.S.
automobile industry. Norilsk had no control over the operations or
budget of the Company other than appointing Directors ? fully
independent of Norilsk, and two of whom are still with Stillwater today
? to constitute a majority of the Board.

CLINTON HAS NOT IDENTIFIED A SUITABLE CANDIDATE FOR CEO

The Clinton Group also indicated in recent materials that they would
have former Stillwater CEO and current director nominee of the Clinton
Group, Charles Engles, serve as the interim replacement CEO of
Stillwater.

The Clinton Group mischaracterizes Dr. Engles′s tenure as Stillwater
CEO, saying he adopted a growth strategy that continues today.

In reality:

• Stillwater struggled under Dr. Engles′s leadership with no clear
  strategy

• Dr. Engles left abruptly after only two and a half years with no
  clear explanation to Stillwater shareholders

While Clinton has referenced unnamed sources that are supportive of Dr.
Engles′s tenure at the Company, this uncorroborated hearsay is
insufficient in validating his murky record as CEO. Stillwater
shareholders deserve an immediate, transparent and forthright
explanation by Dr. Engles himself and the Clinton Group regarding Dr.
Engles′s abrupt resignation from Stillwater in 1997. It is critical that
Stillwater shareholders are made aware of all of the details surrounding
his departure, given the Clinton Group′s misrepresentation of his record
and shortsighted nomination of Dr. Engles as a CEO candidate of
Stillwater in the event Clinton is successful in its takeover of the
Company. Our shareholders deserve to know the full history before being
asked to vote for bringing back an ex-CEO.

CLINTON PUT FORTH AN UNQUALIFIED BOARD SLATE WITHOUT PROPER VETTING

The Clinton Group has put forth a slate of unqualified director
nominees, who are not fit to oversee any U.S. public company, much less
a complex PGM miner such as Stillwater. Furthermore, Clinton has failed
to properly vet its candidates, as is evident in their collective dearth
of qualifications and experience and, in some cases, severe lack of
judgment. The Clinton Group removed John DeMichiei after Stillwater
pointed out serious misstatements in his academic credentials; the fact
that Clinton did not discover and correct this earlier suggests that
they did not perform even the most basic due diligence on their
nominees. Shareholders should not compromise for an unqualified slate of
directors without proper vetting or due diligence.

Stillwater prides itself on its strong core values, including the fair
and just treatment of its employees and unions, and the Company will not
stand by while Clinton attempts to sully Stillwater′s exemplary track
record with a proposed slate of unqualified dissident director nominees.

To highlight a few of Clinton′s director nominees′ most acute
deficiencies:

• John DeMichiei ? After Stillwater called attention to
  inconsistencies in Mr. DeMichiei′s academic record and poor safety and
  labor relations at Signal Peak Energy, Clinton pulled Mr. DeMichiei
  from its slate of director nominees mid-solicitation.
  
• Charles R. Engles ? As noted above, Clinton mischaracterizes
  Dr. Engles′s record as CEO of Stillwater andfails to address
  our request for disclosure of the details about his abrupt resignation
  from the Company. Dr. Engles oversaw Stillwater when it was a
  drastically different company than it is today and he struggled
  mightily; there is no evidence that he has the skills or experience to
  successfully run Stillwater now or in the future.
  
• Seth E. Gardner ? Mr. Gardner′s only public company experience
  consists of nine weeks on Scottish Re Group′s board before it was
  delisted from the NYSE. Despite Clinton′s assertions, he has no
  substantive public company board experience.
  
• Michael 'Mick? McMullen ? Contrary to Clinton′s claims that Mr.
  McMullen understands the operations and financials of nearly every PGM
  company, he has no record of PGM experience. The mining companies he
  has worked with are not PGM miners; the businesses differ drastically
  and his experience is simply not relevant to Stillwater.
  
• Michael McNamara ? Mr. McNamara has no public company board or
  management experience. He is a financial analyst at a small financial
  advisory boutique with only 10 years of work experience, making him an
  unsuitable candidate to serve on Stillwater′s Board.
  
• Brian Schweitzer ? Mr. Schweitzer was a staunch supporter of
  Stillwater while he was in office, and only weeks later he
  inexplicably changed his stance and has chosen to support the Clinton
  Group. Mr. Schweitzer has no public company board or management
  experience and limited management experience outside of politics.
  
• Patrice Merrin ? Despite Clinton′s assertions, Ms. Merrin also
  has no U.S. public company board experience; her tenure on the Council
  on Canadian-American Relations is irrelevant and does not count.
  Furthermore, her ban from the U.S. for involvement with a company that
  worked with the Cuban government is notable and should not be taken
  lightly.
  
• Gregory P. Taxin ? Mr. Taxin has a questionable investment
  history in mining companies and no history whatsoever investing in PGM
  companies. He and the Clinton Group have significantly underperformed
  for public company shareholders.
  

INDEPENDENT THIRD PARTY STAKEHOLDERS BELIEVE IN STILLWATER′S CURRENT
LEADERSHIP

It is important for shareholders to note that Stillwater′s Board and
management team are not alone in favoring the Company′s strategy and
nominees. Several independent parties, who have a comprehensive
knowledge of Stillwater and are impacted by the Company′s operations,
agree with Stillwater, support our incumbent director nominees and have
expressed concern over Clinton′s campaign. Speaking with the Stillwater
County News last month, U.S. Congressman of Montana, Steve Daines,
called Stillwater 'a world-class business? with a strong presence in
Montana.

Likewise, in a letter to shareholders dated April 7, 2013, the United
Steelworkers, the Union that represents many of Stillwater′s employees
has expressed opposition to the Clinton Group′s attempt to replace
Stillwater′s Board of Directors and CEO, stating:

'There is no question about what is best for the success of the
Stillwater Mining Company and the USW′s membership in this upcoming
proxy fight.CEO Frank McAllister and the existing Board of
Directors have done a good job running the Company, and the Clinton
Group′s attempt to replace them is meritless.?

The Good Neighbor Agreement (GNA) Councils have also sent a letter to
Stillwater shareholders, dated April 2, 2013, encouraging them to vote
in support of Stillwater′s plan, saying:

'The Councils appreciate and respect the commitment shown by the
current leadership of SMC over the last twelve years to implement and
promote the GNA.The Councils encourage shareholders of SMC to
vote in support of the current Board and management.?

YOUR INCUMBENT DIRECTOR NOMINEES ARE EXPERIENCED, HIGHLY QUALIFIED
AND DEDICATED TO ALL SHAREHOLDERS

The Company′s incumbent director nominees are far superior to Clinton′s
nominees, who do not have the necessary skills and industry experience
to run a complex PGM miner such as Stillwater. ALL
of Stillwater′s nominees have U.S. public company board experience. ALL
of Stillwater′s nominees have direct experience with PGM mining. Your
current Board is also a positive balance of tenured Stillwater directors
who have helped guide the turnaround of the business as well as recently
added directors who bring a fresh perspective to the Board.

As we look to the future, it is crucial that Stillwater be under the
stewardship of the right directors to leverage the positive momentum
generated in recent years. Stillwater′s nominees are committed to the
development of the Company′s PGM operations and growth programs and
creating value for ALL Stillwater shareholders.

KEEP STILLWATER GOING STRONG ? VOTE FOR
THE STILLWATER NOMINEES

ON THE WHITE
PROXY CARD TODAY

Stillwater is stronger than ever. To ensure that the Clinton Group does
not disrupt your company′s progress, please use your WHITE proxy
card to vote TODAY?by telephone, over the Internet, or by
signing, dating and returning the WHITE proxy card in the
postage-paid envelope provided. You are urged to discard any green proxy
card sent to you by Clinton Group. Even a protest vote against Clinton
Group′s nominees on Clinton Group′s green proxy card will cancel any
previous proxy submitted by you in favor of Stillwater. Please vote
only the WHITE proxy card.

As always, we appreciate all the active engagement on the part of our
shareholders, and thank you for your support.

Best regards,

Francis R. McAllister

Chairman and Chief Executive Officer

Your Vote Is Important, No Matter How Many Or How Few Shares You Own

If you would like to obtain copies of the Company′s proxy materials or
have questions about how to vote your shares, or need additional
assistance, please contact the firm assisting us in the solicitation of
proxies:

INNISFREE M&A INCORPORATED

Shareholders Call
Toll-Free: (877) 825-8906

Banks and Brokers Call Collect:
(212) 750-5833

REMEMBER:

We urge you NOT to vote using any green proxy card sent to you by

the
Clinton Group, as doing so will revoke your vote on the WHITE
proxy card.

About Stillwater Mining Company

Stillwater Mining Company is the only U.S. producer of palladium and
platinum and is the largest primary producer of platinum group metals
outside of South Africa and the Russian Federation. The Company′s shares
are traded on the New York Stock Exchange under the symbol SWC and on
the Toronto Stock Exchange under the symbol SWC.U. Information on
Stillwater Mining Company can be found at its website: www.stillwatermining.com.

Some statements contained in this news release are forward-looking
statements within the meaning of Section 27A of the Securities Act of
1933, as amended, and Section 21E of the Securities Exchange Act of
1934, as amended, and, therefore, involve uncertainties or risks that
could cause actual results to differ materially. These statements may
contain words such as 'believes,' 'anticipates,' 'plans,' 'expects,'
'intends,' 'projects?, 'estimates,' 'forecast,' 'guidance,' or similar
expressions. These statements are not guarantees of the Company's future
performance and are subject to risks, uncertainties and other important
factors that could cause our actual performance or achievements to
differ materially from those expressed or implied by these
forward-looking statements. Such statements include, but are not limited
to, comments regarding expansion plans, costs, grade, production and
recovery rates, permitting, financing needs, the terms of future credit
facilities and capital expenditures, increases in processing capacity,
cost reduction measures, safety, timing for engineering studies, and
environmental permitting and compliance, litigation, labor matters and
the palladium and platinum market. Additional information regarding
factors, which could cause results to differ materially from
management's expectations, is found in the section entitled 'Risk
Factors' in the Company's 2012 Annual Report on Form 10-K and in
subsequent filings with the United States Securities & Exchange
Commission. The Company intends that the forward-looking statements
contained herein be subject to the above-mentioned statutory safe
harbors. Investors are cautioned not to rely on forward-looking
statements. The Company disclaims any obligation to update
forward-looking statements.

Investor:

Mike Beckstead

406-373-8971

or

Innisfree
M&A Incorporated

Arthur Crozier / Jennifer Shotwell / Scott
Winter

212-750-5833

or

Media:

Sard Verbinnen & Co

Dan
Gagnier / Michael Henson

212-687-8080